In the cultivation of many types of plants, a number of structures for housing the growth medium have been designed to enable the grower to closely control the amount of water that is delivered to the plant as well as the integrity of the growth medium. These designs have generally provided a container for the growth medium along with an irrigation system for supplying water and other nutrients to the growth medium and plant roots. As compared to the natural cultivation of plants directly in the ground, the use of containers to house the growth medium has not been as popular due to many factors. The foremost factor is the expense of using a container. An additional expense is due to the rapid depletion of the nutrients in the growth medium. The confining container can also promote the growth of undesirable parasites and fungi, thereby offsetting any advantages in the use of the containers. Finally, evaporation of water from the container can result in salt accumulation at the plant roots which will stunt plant growth or even cause death of the plant itself. The salt accumulation can only be avoided by a significant investment in manually conditioning the growth medium.